EAA Webinar re: Rotax 9-Series Engines

[Matt Ricciardi]

The Experimental Aircraft Association (EAA) is hosting a free webinar on January 22, 2024, regarding installation and operation of Rotax 9-Series engines (i.e., the 912, 915, and 916).  Details and sign-up link here:

https://www.faasafety.gov/SPANS/event_details.aspx?eid=125856

[Matt Ricciardi]

I watched this EAA webinar regarding the Rotax 9-Series engines last night.  The speaker was very knowledgeable and offered a lot of practical information for owners.

I ordered a Rotax 916iS engine, so I tended to pay most attention to those points.  The webinar also covered carburetor issues associated with the 912 engine.  Here were my key takeaways:

• Rotax engines generally make it to TBO, if maintained properly along the way.  The TBO for the 916iS is 2,000 hours -- a major improvement over the 1,200-hour TBO of the 915iS.
• If using 100LL fuel for more than 30% of flight hours, change oil every 50 hours.  If predominantly using unleaded fuels, then you can push the oil change interval to 100 hours.  Use Decalin RunUp Fuel Additive when running on 100LL fuel to scavenge lead and reduce engine buildup.  94UL offers the best of both worlds -- unleaded, consistent, and non-volatile -- but it's not widely available (yet?).
• XPS 5W-50 Full Synthetic Aviation Oil is the only oil approved for use in the 916iS engine.  Do not use the AeroShell 4 Plus Oil approved for the 915iS.
• "Burping" the engine before start-up is not necessary if the dipstick already measures oil within the operating range.  Always burp the engine before adding oil to ensure an accurate measurement; otherwise, you might overfill the oil reservoir.
• Change coolant/antifreeze every 5 years or at TBO, whichever comes first.  Ordinary Prestone automotive coolant is recommended.  Dilute 50/50 with distilled water, or buy the pre-diluted version and use directly out of the bottle.

A recording of the webinar is available on the EAA website here:

https://www.eaa.org/videos/webinars

You need to be an EAA member to access the recording.  The live webinars are free this week.

[Michael Hodes]

Great summary Matt.  I would like to add two additional items:

• The range on the flat section of the oil dig stick is only about 1/2 liter, so be cautious to not overfill.  The speaker suggested 250-300ml is usually fine at any one time.
• Flyrotax.com is a great source for both mechanical and operating directions for the Rotax engines.